Freeze VNDK lib list on release platforms

The list of VNDK libraries that exist in the source tree is compared
against the latest known list. If they are different, build breaks.

The latest list can be updated by running update-vndk-list.sh but it
is allowed only for development branches (i.e. PLATFORM_VERSION_CODENAME
!= REL).

Bug: 67002788
Test: build 2017 pixel devices
Test: m check-vndk-list
Test: update-vndk-list.sh
Change-Id: I4bae2b647c045b11ac7d587fab48067bf53a7cf4